Alternator Problems

[Bludger]

Hello everyone. I hope you all had a nice Christmas?

Following on from my last post, 18813

I have some more questions for you knowledgeable people.
I took my truck into Halfords to get a new alternator fitted before Xmas as I was doing a fair bit of travelling that weekend.

They phoned me saying the alternator definitely wasn't charging the battery, and the replacement that they'd been sent was the wrong one

Anyway, they changed the belts as they were pretty worn, and bolted the old alternator back on and sent me on my way.

That night I fully charged both batteries. Next morning, connected them up and no worries, started first time.

Now here's the good bit -

I've driven from Birmingham to Somerset and back - using my headlights only a bit, and I've driven a total of about 2 hours with headlights on in the past 3 days.

The battery indicator hasn't even moved off about 16 on the gauge

Does this mean my alternator is ok? Were the batteries just so highly charged that they havn't registered a fall in charge yet? I'm at a loss.

I don't want to shell out 300 notes for an alternator I don't need, but I also don't want to be guage watching all the time wondering whether I'm going to cut out at any moment!!

I should be able to get an independent meter test done on Friday, but your thoughts would be most appreciated.

Thanks
Dave

[Gamedawn]

Usually what happens when an alternator "fails" is that the brushes wear to the point where they don't reach the sliprings any more. It may be that by removing and replacing the alternator the brushes have been disturbed and are now making contact again. If the volt meter is showing around the 15-16 volt mark then the alternator is definitely charging.

[TonyN]

Disconnect the batterys while its running, if the dash guage still reads lots of volts then the alt must be OK.

[Bludger]

Disconnect the batterys while its running, if the dash guage still reads lots of volts then the alt must be OK.

Sounds like a plan. I'll give that a whirl. Thanks

[sparkyaj]

put a multimeter over your bat terminals (just one pair) if you have a 12v bat and you read 13v upwards then your alt is working perfectly. if your reading is lower than 12v even by 0.5v then your loosing power.

Sounds like you've sorted the problem though!

should be able to tell with this cold weather too!

[Bludger]

All Sorted !!

Well, I've had the alternator checked by a mate, and he could see no problem with it. Meter was reading 13.18 - 13.26 on both batteries, so everything looks to be running fine.

I'll be on the phone to Halfrauds now demanding to know why they were about to charge me £300 for an alternator I don't need !!

Thanks once again for everyone's help.

[NiftyNev]

Anyway, they changed the belts as they were pretty worn, and bolted the old alternator back on and sent me on my way.

The belts may be why the Alternator was not charging if they were worn and slipping. New belts and problem fixed. Keep an eye on the Alternator charging though and check with the multimeter occasionally to be sure.

Nev

[sparkyaj]

Fantastic. well done!